Shield structure for the face support in mines

ABSTRACT

A mine roof shield and support structure which has a base and a shield, a rocking cap, and a hinged cap supported from the base. The hinged cap and the rocking cap can be independently shifted into engagement with the loads they are to support, and the locations at which the hinged cap and the rocking cap are supported from the base are well behind the end thereof nearer the mine face which keeps the structure from tilting around the front end of the base.

United States Patent 1191 Sigott et al.

Sept. 2, 1975 [54] SHIELD STRUCTURE FOR THE FACE FOREIGN PATENTS OR APPLICATIONS SUPPORT IN MNES 1,232,911 1/1967 Germany 61/45 D [75] inventors: Siegfried Sigott; Alfred Zitz; 1,262,991 2/1972 United Kingdom 61/45 D Heinrich Sussenbeck, all of Zeitweg, Austria Primary Examiner-Jacob Shapiro [73] Asslgme: verein'gte osterreichische Eisen' Attorney, Agent, or Firm-Strauch, Nolan, Neale, Nies und Stahiwerke Alpine Montan & Kurz Aktiengesellschaft, Vienna, Austria [22] Filed: Dec. 26, 1973 [21] Appl. No.: 427,438 [57] ABSTRACT A mine roof shield and support structure which has a [30] Foreign Apphcatmn Pnomy Data base and a shield, a rocking cap, and a hinged cap Dec. 28. 1972 Austria 11113/72 Supported from the base The hinged cap and the rocking cap can be independently shifted into engage- [52] D ment with the loads they are to support, and the loca- [5 i] it. CI- tions at the p and h i g p are [58] Field Of Search 61/45 D, 45 C; 299/31; supported from base are well behind the end 248/35 191/170 MP thereof nearer the mine face which keeps the structure from tilting around the front end of the base. [56] References Cited UNITED STATES PATENTS 8 Claims, 4 Drawing Figures 3,811,288 5/l974 Wchncr 61/45 D PATENTEDSEP' 2i1s sum 1 o 2 FIG./

PATENTED SEP 2 I975 SHEET 2 I]? 2 SHIELD STRUCTURE FOR THE FACE SUPPORT IN MINES The invention refers to a shield structure for the face support in mines. Such a shield structure consists, as a rule, of a base frame, of a shield linked to the base frame and supported against this base frame by at least one prop and of a rocking cap pivotally connected to the shield. The rocking cap is pivotally linked to the shield at the projecting end thereof so that the supporting force is acting on this projecting end. The rocking cap does, however, not allow for an exactly defined introduction of the load at the face. Particularly with fragile roofs of the seam the supporting effect is largely dependent on random events. With known shield structures. the reliability of the supporting action is dependent on the length of the shield, to the projecting end of which the rocking cap is pivotally connected, and further dependent on the length of the base frame underlying the rocking cap. If seen in a top-plan view, the front edge of the base frame is not or not sufficiently underlying the pivotal point of the rocking cap, it will be possible. particularly with weaker sill of the seam, that the shield structure is upset or tilted around the front edge of the base frame. Therefore, with known shield structures, the cantilever of the support for the roof of the seam over the front edge of the base frame is limited and further the length of the base frame is again limited by the longwall transportation means. it is, at any rate. advantageous to advance the hydraulic face support in direction to the face immediately after having passed the under-ground mining machine with consideration of progressive exploitation because in this case the roof of the seam will be supported immediately after having been exposed. This, however, is not possible in those cases in which the base frame of a usual shield structure is only extending till the longwall transportation means. For this reason, shield structures have already been provided in which which the base frame of the shield structure is underlying the longwall transportation means. This will provide the advantage that the shield structure can be advanced immediately after having removed some material at the working face of the seam but will also suffer from the disadvantage that the longwall transportation means must be supported by considerable additional equipment and that the longwall transporation means has to be arranged at a higher level which results in a worse trans portation efficiency and in a reduction of the working height of the under-ground mining machine to be moved on the longwall transportation means.

The invention now aims at avoiding the mentioned drawbacks and essentially consists in that at least one hinged cap is pivotally connected to the shield and the pivotal point ofthe rocking cap or rocking caps is, seen in a top-plan view, arranged for a certain distance behind the front edge of the base frame facing the mine face. noting that the pivotal point of the rocking cap. the pivotal point of the hinged cap and preferably also the engaging point of the prop or props acting on the shield are neighbouring one another. Now, the rocking cap is arranged such that any danger of upsetting of the structure around the front edge of the base frame is reliably avoided. when the rocking cap is subjected to load. By means of this rocking cap the shield structure can be clamped between the roof and the sill of the scam such that any load acting on the projecting hinged cap can no more effect upsetting of the shield structure around the front edge of the base frame. Now, the front edge of the base frame can be arranged with a greater distance from the face of the seam so that there will be a space between the front end of the base frame and the longwall transportation means sufficient for the advancing step so that the shield structure can be advanced immediately after having removed material from the face of the seam and the hinged cap is supporting the roof of the seam with a sufiicient supporting force immediately after having exposed said roof. By the invention it is possible to control the load distribution. The main supporting force and anchoring force will be exerted by the rocking cap, whereas the supporting force exerted by the projecting end of the hinged cap is exerted with a defined magnitude at the face of the seam. According to the invention, the supporting force exerted by the free end of the hinged cap at the face of the seam the free end of the hinged cap is the preferred point of load introduction has a magnitude of approximately 5 to 20 percent of the main supporting force acting on the rocking cap. The resultant force of these supporting forces is located near the point of pivotal connection between the rocking cap and the shield. If this resulting force is acting on the base frame at a location behindthe front edge of the base frame, upsetting of the base frame around this front edge can be avoided. Therefore, according to a preferred embodiment of the invention, the distance between the front edge of the base frame and the point of pivotal connection between the rocking cap and the shield is, seen in a top-plan view, at least one fourth, preferably at least one third. of the length of the bottom of the base frame.

In a preferred embodiment of the invention the rocking cap or caps and the hinged cap or caps are connected to the shield by one or more common pivotal axes, noting that the axis or axes of the prop or props supporting the shield structure are preferably intersecting the pivotal axes. This provides a simple construction. The prop or props supporting the shield against the base frame may advantageously be arranged perpendicular to stratification so that the lowest possible load of the props will result.

To provide the same distance between the free end of the hinged cap and the face of the seam, e.g. coal face, at each height position of the shield structure, the shield may be pivotally linked to the base frame by means of at least one link, noting that the position of said link is defined by a rod, preferably a hydraulic cylinder, of adjustable length and acting on the base frame, at the one hand, and on the link or on the shield or on the pivotal joint connecting the shield with said link, on the other hand.

This arrangement allows for a simple variation of the distance between the-free end of the hinged cap and the face of the seam within certain limits and allows, for instance, within the lower working range of the shield structure and with friable roof of the seam, foreward movement of the free end of the hinged cap till the face of the seam.

A further embodiment of the shield structure described makes it possible to pivotally support within certain certain limits the rocking cap also with its longitudinal axis so that said cap exerting the main supporting force is in the position to accommodate in particularly a reliable manner to any uneveness of the roof of the seam along two planes as, up till now, was only pos sible with frame supports or jack supports.

The invention is further illustrated with reference to the drawing in which various embodiments of the invention are schematically shown.

FIG. 1 shows an embodiment of the invention in a transverse section through the longwall with the shield structure in side elevation.

FIGS. 2 and 3 show two alternate embodiments of the shield structure in a lateral view FIG. 4 shows a cross-section through another embodiment of the pivotal arrangement of the rocking cap.

In the embodiment shown in FIG. 1 the base frame is designated 1 and the shield is designated 2. The shield 2 is pivotally connected to the base frame 1 by means of links 3 and pivotal pins 4 and 5. At the projecting end of the shield 2 a rocking cap 6 is linked for rocking movement around an axis 7. A hinged cap 8 is linked to the shield for swinging movement around the same axis 7. The shield is supported by two props 9 arranged approximately perpendicular to stratification, noting that the upper ends of the props are supported in spherical bearings 10 arranged on the rocking cap 6 and that the lower ends of the props are supported in spherical bearings 11 provided on the base frame. When applying the shield structure, the rocking cap 6 is pressed against the .roof 12 of the seam. Subsequently, the hinged cap 8 is applied by means ofa cylinder l4 acting at 15 on the hinged cap 8 and pivotally connected at 13 to the shield 2. The supporting force is such that the supporting force of the forward end 16 of the hinged cap is 5 to percent of the supporting force exerted by the rocking cap. The resultant force of these two supporting forces is therefore near the axis 7. The lower bearing 11 of the prop 9 is arranged with a distance a from the front edge 17 of the base frame 1. The distance a is more than one third, i.e., nearly one half, of the length b with which the base frame 1 is resting on the sill or floor of the seam. The resulting force of the supporting forces exerted by the free end 16 of the hinged cap on the one hand and by the rocking cap 6 on the other hand will thus reliably be within the supporting area of the base frame 1 so that any upsetting or tilting over the front edge will be impossible. Additionally, the shield structure will be clamped between floor l8 and roof 12 of the seam by means of the rocking cap 6 so that the shield structure will be secured in its position.

The position of the links 3 is defined by a hydraulic cylinder 19, which engages the base frame at 20 and the pivotal point 5 where the shield is pivotally con nected to the links 3. The inclination of the links 3 can thus be adjusted such, that in all height positions of the shield structure the distance between the free end of the hinged cap and the mine face will be the same.

The longwall transportation means is indicated by reference numeral 21. 27 is the advancing cylinder which is supported within the base frame and is engaging the longwall transportation means 21 at 28. The under-ground mining machine can be moved along said transportation means in usual manner on skids. The space requirement for this underground mining machine is indicated by a dot-dash line 22. The outline of the cutting tool is indicated by a dot-dash line 23. 24 is the face of the seam after passing the under-ground mining machine and the drawing is illustrating that the hinged cap 8 is supporting the roof 12 of the seam approximately to the face 24 of the seam. In the drawing, the shield structure is shown in the advanced position after passing the under-ground mining machine, noting that the front edge 17 of the base frame is located immediately adjacent the longwall transportation means 2 I The longwall transportation means 21 is not located above the base frame 1 and thus is resting on the sill or floor 18 of the seam so that in all positions of the shield structure sufficient space for the under-ground mining machine is provided, the outline of which is indicated by dash-dot line 22.

The shield structure shown in FIG. 2 differs from that shown in FIG. 1 only in that the position of the links 3 is defined by a hydraulic cylinder 25 acting at 26 on the shield 2 and on the axis 4 by means of which the links 3 are pivotally connected to the base frame 1.

The embodiment shown in FIG. 3 differs from that shown in FIG. 1 in that for applying the hinged cap 8 a prop 29 is provided which is supported against the base frame 1, is arranged approximately perpendicular to stratification and is linked at 30 to the hinged cap 8.

The arrangement shown in FIG. 4 illustrates an embodiment provided with a rocking cap 6 being movable in longitudinal direction and transverse direction; this corresponds within certain limits to a cardanic suspension of this component part. The hinged cap 8 is pivotally linked to the end 32 of the shield 2 by means of an axis 31. The rocking cap 6 is supported against the base frame 1 by means of two props 9 and is surrounding axis 31 by means of a toroid bearing block. In this manner, the rocking cap 6 can also be allowed to be swivelled in a transverse plane.

What we claim is:

l. A mine roof support and shield structure comprising a base; a shield; means fixing one end of said shield for pivotal movement relative to said base and the other end of the shield above the base; a load bearing rocking cap; means supporting said rocking cap above said base for free pivotal movement about an axis extending transversely of the base; a second, hinged, load bearing cap extending at one end thereof longitudinally beyond said base, the other end of said hinged cap being pivotal relative to the shield and independent of the rocking cap about a transverse axis located above and between the ends of said base; and separate means for independently shifting said rocking cap and said hinged cap into engagement with the loads to be supported thereby.

2. A mine roof support and shield structure as defined in claim I in which the axes about which the rocking cap and said other end of said hinged cap are pivotal are coincidental.

3. A mine roof support and shield structure as defined in claim 1 wherein the horizontal distance between the transverse axis about which the rocking capis pivotal and the edge of the base over which the hinged cap extends is between one-third and onefourth the total length of said base.

4. A mine roof support and shield structure as defined in claim I wherein the means for supporting said other end of said shield includes an upwardly extending prop supported at its lower end from said base.

5. A mine roof support and shield structure as defined in claim 4 in which the longitudinal axis of said prop intersects the transverse axis about which the rocking cap is pivotable and the axis about which said other end of hinged cap is pivotable.

6. A mine roof support and shield structure as defined in claim 5 in which the means for moving the hinged cap into engagement with the load to be supported by said cap includes an extensible. base or shield supported. hydraulic cylinder for pivoting said hinged cap about the transverse axis at said other end of said cap.

7. A mine root support and shield structure as defined in claim 1 in which the means fixing said one end of said shield for pivotal movement relative to said base includes a link pivot-ally fixed at opposite ends thereof to said base and to said one end of said shield. respecside-to-side as well as longitudinally of said base. 

1. A mine roof support and shield structure comprising a base; a shield; means fixing one end of said shield for pivotal movement relative to said base and the other end of the shield above the base; a load bearing rocking cap; means supporting said rocking cap above said base for free pivotal movement about an axis extending transversely of the base; a second, hinged, load bearing cap extending at one end thereof longitudinally beyond said base, the other end of said hinged cap being pivotal relative to the shield and independent of the rocking cap about a transverse axis located above and between the ends of said base; and separate means for independently shifting said rocking cap and said hinged cap into engagement with the loads to be supported thereby.
 2. A mine roof support and shield structure as defined in claim 1 in which the axes about which the rocking cap and said other end of said hinged cap are pivotal are coincidental.
 3. A mine roof support and shield structure as defined in claim 1 wherein the horizontal distance between the transverse axis about which the rocking cap is pivotal and the edge of the base over which the hinged cap extends is between one-third and one-fourth the total length of said base.
 4. A mine roof support and shield structure as defined in claim 1 wherein the means for supporting said other end of said shield includes an upwardly extending prop supported at its lower end from said base.
 5. A mine roof support and shield structure as defined in claim 4 in which the longitudinal axis of said prop intersects the transverse axis about which the rocking cap is pivotable and the axis about which said other end of hinged cap is pivotable.
 6. A mine roof support and shield structure as defined in claim 5 in which the means for moving the hinged cap into engagement with the load to be supported by said cap includes an extensible, base or shield supported, hydraulic cylinder for pivoting said hinged cap about the transverse axis at said other end of said cap.
 7. A mine roof support and shield structure as defined in claim 1 in which the means fixing said one end of said shield for pivotal movement relative to said base includes a link pivotally fixed at opposite ends thereof to said base and to said one end of said shield, respectively, and an extensible hydraulic cylinder pivotally fixed at opposite ends thereof relative to said base and said link, respectively, whereby, by altering the length of said hydraulic cylinder, the position of the link and said one end of said shield relative to said base can be varied.
 8. A mine roof support and Shield structure as defined in claim 1, wherein the means supporting said rocking cap above said base is pivotal in both the longitudinal and the transverse directions relative to the base, whereby said rocking cap can be shifted from side-to-side as well as longitudinally of said base. 